The present invention relates generally to dental impression trays.
In dental applications, an impression is often used to create an imprint or negative likeness of the teeth and adjacent portions of the jaw (e.g., tooth formations, the contour of the gums, etc.) preparatory to dental repair, orthodontics and restoration of missing dental structures. Impressions are typically made by placing a soft, semi-fluid material within the confines of an open trough or channel of an arcuate tray which is then positioned within the mouth of a patient, thus allowing the material to set or cure. Depending upon the material used, the set impression may be either hard or have some elastic characteristics.
To provide the most accurate articulation, the impression cast should generally represent the entire dental arch. In this regard, the impression cast can be used to establish inter-proximal contacts, buccal and lingual contours and occlusion with the opposing teeth. From the negative or female cast of the teeth and surrounding structures, a positive reproduction or male cast may be created for the purpose of fabricating inlays, crowns, bridge retainers, dentures, restorations or the like.
Traditionally, before an impression cast of the dentition is created, a stock tray is selected by the dentist or dental assistant that will generally fit the dental arch of the particular patient. Since the dental arch may differ widely from patient to patient, various sizes of impression trays (e.g., small, medium and large) were developed by those skilled in the art to accommodate various mouth sizes, bite radii of teeth and to correspond to upper and lower anterior or quadrant impression sites.
As described in U.S. Pat. No. 6,629,841, certain dental impression trays formed of metal, such as stainless steel, have a pair of spaced-apart vertical walls joined by a semi-rigid mat or mesh material disposed horizontally between the opposing vertical walls. Extending outwardly in structural relation to at least a portion of the surface facing of one of the vertical walls, a handle member may be provided to facilitate a means for gripping the impression tray for purposes of manual manipulation. In addition, an open trough or channel is generally formed between the opposing vertical walls, wherein the horizontally disposed mesh material provides porous surface flooring for the trough. In operation, the mesh material provides a means for permitting excess flow of impression material to become displaced and extruded there through. Dental impression trays of the prior art may further include openings formed in the vertical walls of the trough or channel which generally function as an anchoring surface for the impression, thus allowing the excess flow of impression material to become attached thereto.